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5 steps on how to do an auto radiator flush

A mistake many vehicle owners make is that of overlooking the maintenance of their vehicle’s radiator and cooling system. Often, owners only think about the cooling system at the start of winter or summer, when they remember to check the coolant or antifreeze level, or when it’s too late and they get into trouble with an overheating engine. Car owners often don’t think about just how important radiator flush is. Could you be one of these owners?

A properly functioning radiator is essential to prevent your vehicle’s engine from overheating. Liquid coolant, heated by the engine, is channelled through the radiator, where it is cooled by heat exchange before re-circulating through the engine again to pick up more heat, and repeating the process over and over again.

Radiator cleaning – how to flush a radiator?

It’s important to remember that your vehicle’s radiator and cooling system needs to be clean in order for it to be able to carry out the above process effectively.

Over time, however, solid deposits or sludge builds up in a vehicle’s radiator that can clog the cooling system, making the cooling process less effective and potentially hurting the performance of the engine.

Doing a quick, inexpensive car radiator flush every two years or 30,000km (whichever comes first) can keep your vehicle’s cooling system in shape and your vehicle running smoothly.

The 5-step car radiator flush

To keep your vehicle’s radiator clean and cool, and operating as it should, follow these 5 steps on how to do an auto radiator flush.

Step 1: Prepare to drain the old coolant

Ensure the engine is completely cool – in other words, your vehicle’s engine hasn’t been running for at least two hours.

Make sure you have a suitable wide-mouth container ready into which the coolant or antifreeze can drain. The container must be large enough to hold all the radiator fluid that comes out – and you’re going to do the process twice so you’ll need to be able to collect twice the volume of fluid that’s in your radiator. Coolant is very toxic so you will need to dispose of the collected fluid appropriately.

You’ll also need to have the appropriate radiator flush solution on hand for use after you’ve drained the radiator.

Step 2: Drain the old coolant

Then look beneath the radiator for the drain plug (either a screw plug or bolt plug) or petcock. Be sure you have the receptacle for the used coolant in place under the drain before you open it. Let the coolant completely drain out of the radiator and into the receptacle.

Step 3: Add the radiator flush solution

Once all the coolant has drained from the radiator, close the drain plug or petcock.

Now pour the radiator flush solution into the radiator and fill with water. Then screw on the radiator cap tightly and start the engine.

Let the engine run until the temperature gauge reaches its normal operating temperature.
At this point, turn on the vehicle’s heater and set the temperature control to the hottest position and highest fan setting.

Let the engine run like this for 10 minutes, then shut it off and let the engine cool completely again.

Step 4: Drain the radiator flush solution

Once the engine is cool again, repeat the process in Step 2 until all the radiator fluid has once again drained into the latch receptacle. The radiator fluid will also contain residue coolant flushed from the system which makes it just as toxic as the first lot that you drained, so be sure to dispose of it appropriately.

Step 5: Refill the radiator with new coolant

Once all the fluid has drained from the radiator, close the drain plug or petcock.

Now that you’ve successfully performed an engine coolant flush, all that now remains to be done is to refill the radiator with fresh coolant. Check your vehicle owner’s manual to ensure you use the right type of coolant for the vehicle’s cooling system and that you mix the coolant and water to the right ratio.

Using a funnel to eliminate spills, fill the radiator with the right mix of coolant and water, usually a 50/50 mixture, but make sure you check what’s right for your vehicle. Once the radiator is full, also fill the plastic coolant reservoir if your vehicle has one, again with the appropriate coolant/water mix.

Replace and tighten the radiator and coolant reservoir caps and start the vehicle. Let it run and check for any leaks.

Well, there you have it – the basics of how to flush a radiator. It’s also a good idea to check the radiator’s coolant level over the next day or so to make sure everything is still looking good.

Do you want the best radiator flush?

A faulty radiator can lead to all sorts of problems, including very expensive ones and the hassle of breaking down when and where you can least afford it. That’s why radiator maintenance is so essential to help your radiator keep its cool and ensure the health of your vehicle’s engine.

However, keeping a radiator happy and cool involves more than merely flushing it from time to time. While that is good, other aspects of the cooling system need to also be checked regularly. That’s why ADRAD’s nationwide network of radiator specialists offer more than just a radiator flush service.

In addition to doing a machine-powered radiator flush, our radiator experts will assess the overall health of your vehicle’s radiator and cooling system. We’ll service it fully, including doing a comprehensive system inspection and pressure checking and testing for any leaks.

We cater for all types of vehicles and our radiator repair specialists will take expert care of all your auto radiator repair needs, guaranteeing expert craftsmanship, quality products and service.

If it’s time for your vehicle’s routine radiator flush, simply give us a call on 0800 RADIATOR (723 428) and we’ll get it done expertly for you. Call us today.